(1) Field of the Invention
This invention relates to concrete mixers and more particularly, to an auger swivel for concrete mixers.
(2) Description of the Prior Art
Concrete mixers mounted to the chassis of vehicles are known in the art. These concrete mixers make concrete by mixing aggregate, cement and water together in either one mixing bin, mixing augers, or by other mixing apparatuses. The mixers travel to one or more work sites and selectively deposit a predetermined amount of concrete at each site. A dispensing trough or a mixing auger usually is positioned manually or mechanically over the work site so that the concrete can be properly dispensed, depending on the size and weight of the trough or mixing auger.
A mechanically positioned mixing auger, for example, usually includes both a device to raise and lower a dispensing end of the mixing auger and a swivel to rotate the dispensing end into place. A gear and chain driven mechanism is commonly used to rotate the mixing auger for positioning the dispensing end of the mixing auger. The gears tend to wear quickly since hardened concrete adheres to the chain causing excessive wear to the gear teeth. Furthermore, the chain tends to stiffen as the hardened concrete accumulates on the chain. This causes an increase in the amount of torque required to rotate the gear chain. Typically, an electric motor is used to turn the chain. The increase in required torque can easily stall the motor and limit the useful life of the motor.
Therefore, it is an object of this invention to increase the operating life and reduce the maintenance of a swivel over that of the prior art.
It is a feature of this invention to have a linkage arrangement, rather than a gear and chain mechanism to drive the swivel. This permits improved operating performance in a dirty environment.
It is an advantage of this invention that when concrete adheres to the linkage, the swivel is much less affected than that of the prior art.